<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
	.father {
		border: 1px solid red;
		width: 300px;
		overflow: hidden;   /*别加错位置了，给 父亲加*/
		/*不是所有的浮动我们都需要清除 ，谁影响布局，我们清除谁*/
	}
	.big {
		width: 100px;
		height: 100px;
		background-color: purple;
		float: left;
	}
	.small {
		width: 80px;
		height: 180px;
		background-color: blue;
		float: left;
	}
	.footer {
		width: 400px;
		height: 100px;
		background-color: pink;
	}
	</style>
</head>
<body>
	<div class="father"> 
		<div class="big"></div>
		<div class="small"></div>
	</div>
	<div class="footer"></div>
</body>
</html>